Apparatus for producing loops on coil springs



G. A. REDDINGTON APPARATUS FOR PRODUCING LOOPS ON COIL SPRINGS 2 Sheets-Sheet 1 March 19, 1968 Filed July 19, 1965 INVENTOR.

GEORGE A. REDDINGTON 4W I A ORNEYS March 19, 1968 G. A. REDDINGTON 3,373,775

APPARATUS FOR PRODUCING LOOPS ON COIL SPRINGS Filed July 19, 1965 2 Sheets-Sheet 2 INVENTOR.

6501205 A- REDDINGTON K F AT RNEYS United States Patent f ABSTRACT OF THE DISCLOSURE An automatic spring looping apparatus is described which is simple and has a minimum number of moving parts. The apparatus comprises two spring supporting members mounted adjacent one another on a mounting plate and each of which has an open ended spring receiving and locating bore. The first of the spring supporting members is mounted for rotation between a spring receiving and loop forming position and a spring transfer position in which its bore is coaxially aligned with the bore of the second supporting member, and the second member is rigidly mounted on the plate. Loop forming mechanism associated with each of the spring supporting members at an open end thereof includes an anvil for engaging a spring within the bore and maintaining it in position at the end of the bore during formation of a loop on its end. The anvil of the loop forming mechanism associated with the second spring supporting member is retractable from in front of the open end of the bore to permit a spring to be ejected through such end after a loop is formed on it.

This invention relates to the production of loops on the end of coil springs and is more particularly directed to improved apparatus for bending outward the terminal coil on each end of a coil spring to thereby provide loops on the spring ends. 1

It is common to form loops on the ends of a coil spring by bending the terminal coil on each end outward in order to provide means for attaching the spring between two members. Until recently it has been necessary to form these loops on springs by hand. Now, however, the art has advanced to the stage in which automatic apparatus is provided for this purpose. For example, my Patent No. 3,183,944 issued May 18, 1965, and my copending application Ser. No. 439,705 filed Mar. 15, 1965, now Patent No. 3,336,953, describe and claim apparatus of this type having many desirable features.

It is an object of the present invention to provide an improved apparatus for forming loops on a coil spring which is simple in operation and has a minimum number of moving parts.

Another object of the invention is to provide such an improved apparatus which provides a loop on both ends of coil springs in an exceptionally fast yet simple manner.

Still another object of the invention is toprovide an improved apparatus for forming terminal loops on a coil spring and which includes a retractable anvil and means for retracting the anvil while still providing rigid support for the anvil during a loop forming operation.

A further object of the invention is to provide an improved spring loop forming apparatus which is readily adjustable to accommodate springs of dilferent sizes.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be 3,373,775 Patented Mar. 19, 1968 adopted within the scope of the invention as set forth in the claims.

Referring to the drawings:

FIGURE 1 is a front elevational view of a preferred embodiment of the loop-forming apparatus of the invention depicting the spring locating and loop forming mechanisms thereof;

FIGURE 2 is a back elevational view of the embodiment of FIGURE 1 depicting driving cylinders for providing power to the moving mechanism of the invention;

FIGURE 3 is a fragmentary, partly cross sectional View of a portion of the apparatus of the invention depicting it in one position of its operation;

FIGURE 4 is a fragmentary, partly cross sectional view similar to FIGURE 3 showing the depicted apparatus in another position of its operation;

FIGURE 5 is a fragmentary elevational view partly in section taken along a plane indicated by the line 55 of FIGURE 1;

FIGURE 6 is a cross-sectional view taken along a plane indicated by the line 6-6 of FIGURE 5 and depicting particulars of the invention; and

FIGURE 7 is a cross sectional view of a rotatable spring receiving and locating member of the loop forming mechanism of the invention. 3

A preferred embodiment of a loop forming apparatus of the invention is shown in the drawings and is generally indicated therein by the reference numeral 1 1. In its broad aspects the apparatus includes two spring support members 1'2 and 13 having associated therewith two loop forming mechanisms 14 and 16 respectively. Support member 12 and loop forming mechanism 14 coact to form a loop in a first end of a coil spring, while support member 13 and loop forming mechanism 16 provide a loop on the second end of the spring. More particularly, the support members 12 and 13 are mounted adjacent to one another on a mounting plate 17 with the support member being rigidly mounted thereon and the support member *12 being mounted for rotation between a spring receiving and loop forming position, shown in FIGURE 3, and a spring transfer position, shown in FIGURE 4.

When support member 12 is in the loop forming position depicted in FIGURE 3, an unlooped spring can be introduced therein from a suitable means such as feed tube 15. The spring is then axially advanced and rotated within the support member, such as by means of air, into a loop forming position in abutment with an anvil 18 of the loop forming mechanism 14. A pick 19 of the loop forming mechanism then moves downward to engage the final loop of the spring and bend it outward in a known manner to form a loop on a first end on the spring.

After the first loop is formed, support member 12 is rotated a small angular distance about its transverse axis to the spring transfer position shown in FIGURE 4 whereat air is introduced through a tube 21 to transfer the spring from support member 1'2 to support member 13. Thespring is axially advanced within the support member and oriented in abutment with an anvil 22 of loop forming mechanism 16. Pick 23 of the loop forming mechanism 16 can then coact with anvil '22 to form a loop on the second end of the spring in a manner similar to the manner in which the first loop is provided.

It is to be noted that before the second loop is formed on the spring, the first spring support member returns to its looping forming position and another spring is introduced therein. The picks 21 and 23 are then reciprocated simultaneously to form loops on both springs at once.

Mechanism is provided for retracting the anvil 22 so that a Spring can be ejected from the support member 13 after loops have been formed in both ends of it. That is, as best depicted in FIGURES 5 and 6, anvil 22 is mounted for reciprocal motion on plate 17 by means of a dovetail arrangement to be more fully described hereinafter. Means, such as spring 24, is provided to resiliently urge the anvil downward, and a wedge ram 26 is provided to move the anvil upward to its loop forming position by engaging an oblique wedge surface 27 on the anvil mounting.

From the above, it is seen that the spring looping apparatus of the invention has a minimum of moving parts. That is, besides the picks 19 and 23, the only moving parts are the rotatable spring member "12 and the retractable anvil 22. Thus, the apparatus is simple in its operation and requires only a minimum of maintenance. Furthermore, the distance of movement of these parts is very little and for this reason, besides the fact that loops are formed on two springs simultaneously, the apparatus is extremely fast.

The wedge and spring arrangement for reciprocating anvil 22 assures fast and positive movement of the anvil, while still providing for rigid securance of the anvil by wedge ram 26. Because of this rigid securance, there is no tendency for the anvil to move downward and provide a malformed loop when the pick 23 is reciprocated against it.

Considering the invention now in more detail, it is to be noted that the loop forming mechanism and spring support members are all on one side of the mounting plate 17, while the driving mechanisms for the movjng parts are on the opposite side of the mounting plate. This separation of the driving mechanism from the working apparatus facilitates the depicted placement of the working apparatus as well as providing for easy accessibility thereto.

To simplify the manufacture of the spring support members as well as to permit them to be interchanged, the support members 12 and 13 are themselves identical. More particularly, each of the support members comprises a discoidal plate 28 having an outwardly extending nipple 29. Plate 28 is secured by means of two bolts 31 and pin 32 to an annular member 33 (one of which is shown in FIGURE 7) having a sleeve 34 extending through plate 17. It is to be appreciated that while the annular member to which support member 13 is secured is rigidly mounted onto plate 17, the annular member to which support member 12 is secured is, as is shown in FIGURE 7, rotatably mounted to plate 17 by means of bearing assembly 36 surrounding the sleeve 34.

A rectangular boss 37 projects outward from each of the support members and has a central passage within which is a tubular cylinder 38. The cylinders 38 define spring receiving and locating bores 39 which are similar to those described in the above mentioned patent and patent application. As shown in FIGURE 1, cylinders 38 are secured within their respective bosses 37 by means of set screws 40. The provision of these set screws permit cylinders having different sized bores to be placed within the bosses so that the apparatus is capable of handling different sized springs.

Means are provided for axiallyadvancing and rotating a spring within each of the support member bores to a loop forming position against the anvil of its associated loop forming mechanism. More particularly each of the support members has an axial air passage 41 extending through its nipple 29 to the central passage through its boss 37. An annular groove 42 is provided centrally of the outer periphery of each tubular cylinder and is adapted to communicate with its associated air passage 41. This groove, in turn, communicates with an air jet inlet passage 43 extending through the tubular cylinder to the spring receiving and locating bore therein. This air jet passage is obliquely inclined with respect to bore 39 and its axis so that air issuing therefrom will form a helical air current to both axially advance and rotate a spring within the bore into loop forming position against an anvil in the manner described in my earlier mentioned patent and patent application. It is to be noted that each of the tubular cylinder bores has a relief groove 44 to permit the proper rotation within the bore of a spring which already has a loop formed on one end. While this relief groove has no real purpose in support member 12 because springs to be positioned therein do not have loops, the provision of the groove in this cylinder assures that the tubular cylinders are identical and can be inter' changed.

Conventional means, such as the escapement mechanism generally indicated by the reference numeral 46 in FIGURE 1, can be provided to control the time at which an unlooped spring is fed to support member 12 and to assure that only one spring is fed at a time. As will become apparent hereinafter, all driving mechanisms of the invention are air operated and for the sake of simplicity it is desirable that the escapement mechanism also be driven by air. To this end, an air jack 47 is operatively connected to escapement mechanism 46 to provide its motivation.-

As depicted in FIGURES 1 and 5, both anvil 18 and anvil 22 are mounted so that their position with respect to the support members can be adjusted. That is, each anvil is mounted on an angle bar 48 which, in turn, is mounted within a groove 49 (see FIGURE 5) in a tenon member 51 for sliding adjustment therein toward and away from the support members. Tenon member 51 is mounted between mortise defining flanges 52 so that it can be translationally adjusted toward or away from plate 17. Thus the anvils can be adjusted both transversely to and parallel to the plate 17. This ability to adjust the anvils 18 and 22 with respect to their respective support mem bers assures that they can always be properly aligned and allows their position to be changed to enable various sized springs to have loops formed thereon.

It is important to note that while the mortise defining flanges 52 associated with the anvil 18 are rigidly mounted to plate 17, the corresponding mortise flanges associated with anvil 22 are mounted to a rectangular block 53. This block has other mortise flanges 54 in sliding engagement with a tenon 55 which is in turn rigidly mounted to plate 17. It is the dove-tail arrangement provided by the block 53 and tenon 55 which acts as a guide for the anvil 22 in its movement between its loop forming position and its retracted position.

The lower end of block 53 has a downwardly extending flange 56 defining aforesaid wedge surface 27 which is engageable by the wedge ram 26 to provide the desired upward movement of anvil 22 from its retracted position to its loop forming position. Block 53 also is provided at its upper end with an upwardly extending pin 57 which slidably passes through a rigidly mounted stop 58. Compression spring 24 is held in position between stop 58 and the block 53 by means of pin 57. As mentioned before, this spring resiliently urges anvil 22 downward toward its retracted position. In order to assure fast retraction of the anvil 22 upon wedge ram 26 being moved out of engagement with wedge surface 27, spring 24 should have a high compressive strength.

Wedge ram 26 can be reciprocated by any suitable means, however, desirably the reciprocation of the ram is by means of an air jack 59. It is to be noted that a collar 60 is provided on the rear side of plate 17 to define a guide for the wedge ram.

Picks 19 and 23 are each provided with a tenon 61 which is slidable within a mortise defined by a block 62 extending outwardly away from mounting plate 17. These blocks provide a guide for movement of the picks and, while not shown, can be mounted for suitable adjustment with respect to plate 17 and the support members in a manner similar to the manner in which the anvils are mounted. In order to provide the desired reciprocal motion to the picks, each is pivotally mounted to a lever arm 63 which is, in turn, mounted to a journal 64 which passes through the plate 17. A crank 66 is secured to each journal 64 on the far side of the plate, and it is seen that on arcuate movement of such crank, the picks will reciprocate toward and away from their respective anvils to provide a loop on the end of a spring. Suitable means 'such as the air jacks 67 are provided on the far side plate 17 and secured to cranks 66 to provide the desired arcuate movement thereof. It is to be noted that adjustable stops 68 are provided for engagement by the cranks 66 to limit their upper movement and thereby prevent overtravel of the picks.

A similar arrangement is provided for rotating support member 12 between its loop receiving position and its loop transfer position. That is, the sleeve 34 of the mounting for support member 12 has a crank arm 69, rigidly secured thereto on the far side of plate 17. This crank is also driven by an air jack '67, and there are stops 71 to limit the movement of crank arm 69 to assure proper positioning of the support member 12 in its two positions.

Air conduits 72 are connected to each of the support member mounting sleeves 34, and also to the air jacks 67 so that pressurized air can be selectively introduced to the apparatus from a suitable source. It is to be appreciated that a suitable controlling means, such as solenoidally operated valves, can be provided for controlling the time of introduction of air to each of the cylinders as well as to the bores of the spring receiving and locating bores.

From the above, the simplicity of the apparatus and its advantages should be readily apparent. For example because support member 12 is adjacent to support member 13 and its bore axis is planar with the bore axis of such support member, a slight rotation thereof will coaxially align the bores. This slight rotation can be accomplished in a minimum of time and with a minimum of apparatus. Further, the wedge arrangement for moving the retractable anvil assures positive movement of the anvil and rigid positioning thereof in the loop forming position.

What is claimed is:

1. Apparatus for forming a lop on each end of a coil spring comprising first and second spring support members mounted adjacent one another and each of which has an open ended spring receiving and locating bore, the second of said spring support members being rigidly mounted and the first thereof being mounted for rotation between a spring receiving and loop forming position and a spring transfer position in which the bore thereof is coaxially aligned with and adjacent the bore of said second member, a loop forming mechanism associated with each of said spring support members at an open end thereof and which includes an abutment for engagement with a spring within the bore of its associated support member at said open end for maintaining said spring thereat during the formation of a loop on the end of said spring, the abutment of the loop forming mechanism associated with said second support member being selectively retractable from in front of said open end of the bore to permit a spring to pass through said open end.

2. Apparatus for forming a loop on each end of a coil spring comprising first and second spring support members each of which has an open ended spring receiving and locating bore, the second of said spring support members being rigidly mounted and the first thereof being mounted adjacent said second member for rotation about an axis transverse to its bore between a spring receiving and loop forming position in which the axis of its bore is planar with and angularly related to the axis of the bore of said rigidly mounted second member and a spring transfer position in which the bore thereof is coaxially aligned with and adjacent the bore of said second member, a first loop forming mechanism associated with said first spring support member and mounted to be adjacent an open 6. end of the bore thereof when said first member is in said spring receiving and loop forming position, a second loop forming mechanism associated with said second spring support member and mounted adjacent an open end of the bore thereof, said second loop forming mechanism including an abutment normally in front of said open end for engaging a spring and maintaining said spring within said boreat said open end during the formation of a loop thereon, said abutment being selectively retractable from in front of said open end to permit a spring to pass through said open end.

3. The loop forming apparatus of claim 2 in which said abutment is a loop forming anvil, and which includes resilient means for urging said anvil to a retracted position, and a reciprocal wedge ram for engaging a wedge face associated with said anvil for moving said anvil against the force of said resilient means to a loop forming position at said bore open end.

4. In an apparatus for forming a loop on a coil spring, the combination comprising a spring support member having a spring receiving and locating bore therein with an open end, a loop forming mechanism adjacent said open end including an anvil against which one end of a spring within said bore is to be abutted, said anvil having associated therewith a wedge face and being translationally movable between a loop forming position obstructing movement of a spring through said open end and a retracted position permitting such movement, resilient means for urging said anvil to said retracted position, and a reciprocal wedge member for engaging said anvil wedge face to translationally move said anvil against the force of said resilient means to said loop forming position.

5. Apparatus for forming a loop on each end of a coil spring comprising first and second spring support members mounted adjacent one another and each of which includes a tubular cylinder having an open ended spring receiving and locating bore, the second of said spring support members being rigidly mounted and the first thereof being mounted for rotation between a spring receiving and loop forming position and a spring transfer position in which the bore of the cylinder thereof is coaxially aligned with and adjacent the bore of the cylinder of said second member, a loop forming mechanism associated with each of said spring support members at an open end thereof and which includes an anvil for engagement with a spring within the bore of its associated support member at said open end, means for axially advancing and rotating a spring in the bore of each of said support members into a loop forming position in abutment with its associated anvil, and means for selectively retracting the anvil associated with second support member from in front of said open end to permit a spring to pass through said open end thereof.

6. The loop forming apparatus of claim 5 in which said means for axially advancing and rotating a spring in said bore includes air jet means and said means for retracting said anvil include resilient means for urging said anvil to a retracted position, and a reciprocal wedge ram for engaging a wedge face associated with said anvil for moving said anvil aaginst the force of said resilient means to a loop forming position at said bore open end.

References Cited UNITED STATES PATENTS 3,040,784 6/1962 Ashley-Wing -103 3,156,269 11/1964 Lehtonen 14010'3 3,183,944 5/1965 Reddington 140-103 3,253,622 5/1966 Hammersmith 140l03 CHARLES W. LANHAM, Primary Examiner. E. M. COMBS, Assistant Examiner. 

